What is the rule of 30-60-90 triangles

Find the measure of the interior angles of the following regular polygons: a triangle, a quadrilateral, a pentagon, an octagon, a decagon, a 30-gon, a 50-gon, and a 100-gon.

Which statement best explains why ben uses the width hi to create the arc at j from point k

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)